Conventional art for coating an LED with a fluorescent material using an exposure apparatus includes a method of applying a polymer material such as epoxy, into which the fluorescent material is mixed, onto the LED, and then curing the polymer material. In general, a packaging process is performed by applying a fluorescent material to the entire surface of the LED after completion of wire bonding. Therefore, when the LED coated with the fluorescent material does not have desired performance, the LED, into which a high manufacturing cost has been invested because the wire bonding process was already performed, should be disposed of, and thus the overall manufacturing cost may be increased.
In addition, in the conventional method of coating an LED with a fluorescent material, it may be difficult to control the thickness of the polymer material containing the fluorescent material. To resolve those problems, Korea Patent Publication No. 10-2009-0076101 discloses technology for controlling the coating thickness of a photoresist containing a fluorescent material by applying a photoresist including the fluorescent material onto a substrate on which LED chips are arranged, and then selectively exposing the photoresist.